A Simple Generic Vector Container in C

I do not see much need to have a vector container in C as a vector is simply an array and array operations are all very simple. Nontheless, it might still better to implement one, for the sake of completeness. Here is the code. The library is almost as fast as the fastest code you can write in C.

#ifndef AC_KVEC_H
#define AC_KVEC_H

#include
#include

#define kv_roundup32(x) (–(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))

#define kvec_t(type) struct { uint32_t n, m; type *a; }
#define kv_init(v) ((v).n = (v).m = 0, (v).a = 0)
#define kv_destroy(v) free((v).a)
#define kv_A(v, i) ((v).a[(i)])
#define kv_pop(v) ((v).a[–(v).n])
#define kv_size(v) ((v).n)
#define kv_max(v) ((v).m)

#define kv_resize(type, v, s) ((v).m = (s), (v).a = (type*)realloc((v).a, sizeof(type) * (v).m))

#define kv_push(type, v, x) do { \
if ((v).n == (v).m) { \
(v).m = (v).m? (v).m<<1 : 2; \ (v).a = (type*)realloc((v).a, sizeof(type) * (v).m); \ } \ (v).a[(v).n++] = (x); \ } while (0) #define kv_pushp(type, v) (((v).n == (v).m)? \ ((v).m = ((v).m? (v).m<<1 : 2), \ (v).a = (type*)realloc((v).a, sizeof(type) * (v).m), 0) \ : 0), ((v).a + ((v).n++)) #define kv_a(type, v, i) ((v).m <= (i)? \ ((v).m = (v).n = (i) + 1, kv_roundup32((v).m), \ (v).a = (type*)realloc((v).a, sizeof(type) * (v).m), 0) \ : (v).n <= (i)? (v).n = (i) \ : 0), (v).a[(i)] #endif [/sourcecode]